The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Vehicles use powertrain systems to generate and transfer tractive torque to an output member. Known hybrid powertrain systems for motor vehicles include internal combustion engines and torque machines that transfer tractive torque to one or more drive wheel(s), including transferring torque through a transmission device to the output member coupled to a driveline. One known hybrid powertrain system includes electric machines configured to operate as torque motors and electric power generators that exchange electric power with an electrical energy storage device.
Hybrid powertrain systems include internal combustion engines mechanically coupled in series with one or more torque machines, including range-extended electric vehicles and plug-in hybrid electric vehicles that use electric power for propulsion.
One known internal combustion engine includes a reciprocating internal combustion engine having two opposing cylinders with a double-ended free piston oscillating therein. The double-ended free piston in the opposing cylinders forms two variable volume combustion chambers. The opposing cylinders can have a linear electrical alternator integrated therein, and the double-ended free piston includes a plurality of permanent magnets. When the free piston oscillates in the two opposing cylinders during operation of the engine, electrical energy is generated that can be used to power a torque machine or can be stored in an electrical energy storage device. The operation thus directly converts chemical energy in the form of engine fuel to electrical energy and power.